Deciphering the code between air pollution and disease: The effect of particulate matter on cancer hallmarks

International Journal of Molecular Sciences – In this review, researchers summarize and discuss the evidence regarding the effect of particulate matter (PM) and its impact in carcinogenesis, considering the “hallmarks of cancer” including sustained proliferative signaling, evasion of growth suppression, resistance to cell death, acquisition of replicative immortality, angiogenesis induction, and activation of invasion and metastasis. They found that exposure to particulate matter induces multiple hallmarks of cancer seen during tumor development.
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The CAREX Canada team offers two regular newsletters: the biannual e-Bulletin summarizing information on upcoming webinars, new publications, and updates to estimates and tools; and the monthly Carcinogens in the News, a digest of media articles, government reports, and academic literature related to the carcinogens we’ve classified as important for surveillance in Canada. Sign up for one or both of these newsletters below.

CAREX Canada

Faculty of Health Sciences

Simon Fraser University
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2602 – 515 West Hastings St
Vancouver, BC  V6B 5K3
CANADA

© 2020 CAREX Canada

New report examines challenges and opportunities around setting an occupational exposure limit for diesel engine exhaust in Canada

Diesel engine exhaust (DEE) is one of the most prevalent occupational exposures in Canada, with approximately 897,000 Canadians exposed at work. It is a known human carcinogen, according to the International Agency for Research on Cancer (IARC), with links to lung cancer (sufficient evidence) and bladder cancer (limited evidence). According to the Burden of Occupational Cancer Study, workplace DEE exposure is responsible for approximately 560 lung cancers and possibly 200 suspected bladder cancers, with new diagnoses costing approximately $684 million per year.

Current scientific evidence supports the need for a more protective occupational exposure limit (OEL) for DEE in Canada. In order to better understand the regulatory landscape for occupational DEE exposure in Canada and identify key barriers and facilitators to setting and complying with OELs, our team conducted interviews with key informants and an environmental scan of OELs for DEE. The results are presented in the new report, “Setting an Occupational Exposure Limit for Diesel Engine Exhaust in Canada: Challenges and Opportunities”.

With the exception of the mining industry, our results show that few jurisdictions in Canada have an OEL for DEE, and none have adopted an OEL that reflects the current state of knowledge. OELs exist for various components of DEE (e.g., carbon monoxide, oxides of nitrogen), but there is a regulatory gap for limiting exposure to the carcinogenic fraction, which is mainly found in the particulate matter.

 

Table 1: Adopted or recommended OELs for DEE in Canada

Jurisdiction OEL Marker of exposure Notes/Policy instrument reference
CAN 8-hr TWA: 1.5 mg/m3 Respirable combustible dust  
BC 8-hr TWA: 1.5 mg/m3 Respirable combustible dust Applies to mines and to to any underground working which is not a mine within the meaning of the Mines Act.
SK 8-hr TWA: 0.16 mg/m3 Total carbon Applies to mines, as defined by the Mines Regulations, 2018.
ON 8-hr TWA: 0.4 mg/m3 Total carbon Current OEL; applies to all mines, mining plants, and mining development in Ontario. Method: NIOSH 5040.
8-hr TWA: 0.16 mg/m3 Total carbon; respirable dust Proposed OEL. Would apply to workplaces in which Regulation 833 applies. Method: NIOSH 5040.
QC 8-hr TWA: 0.4 mg/m3 Total carbon Applies to a mine, as defined by the mining OHS regulations. Method: NIOSH 5040.
NL 8-hr TWA: 0.4 mg/m3 Total carbon Applies to underground mines. Measured as per NIOSH Method 5040.
NB 8-hr TWA: 1.5 mg/m3 Respirable combustible dust Applies to underground mines.
NS 8-hr TWA: 1.5 mg/m3 Respirable combustible dust Applies to non-coal mines.
YK 8-hr TWA: 1.5 mg/m3 Respirable combustible dust Applies to mines, as defined under the OSH regulations.
NWT 8-hr TWA: 1.5 mg/m3 Respirable combustible dust Applies to mines.
NU 8-hr TWA: 1.5 mg/m3 Respirable combustible dust Applies to mines.

 

Diesel engine exhaust contains up to 1,800 chemicals, making it a complex mixture that is challenging to monitor. However, elemental carbon has emerged as the best surrogate for measuring diesel exhaust particulate and several international jurisdictions have proposed or adopted OELs based on measurement of elemental carbon, including Switzerland, Germany, and Austria (see report for more details).

The interviewees identified several key challenges to developing and implementing a DEE OEL, including:

  • Perceived scientific uncertainty and a lack of consensus about the best marker of exposure
  • The slow pace of regulatory change
  • Resistance of employers at the perceived costs of implementation
  • The uneven occupational health and safety landscape that exists within Canada
  • The absence of an ACGIH® TLV for DEE

Most jurisdictions in Canada set OELs based on the American Conference of Governmental Industrial Hygienists (ACGIH®) Threshold Limit Values (TLVs), which has not yet issued a recommendation for DEE. The absence of an ACGIH® recommendation on DEE appears to be one of the principal reasons why there is currently no OEL for DEE in Canada.

The key facilitators to developing and implementing an OEL for DEE the interviewees identified include:

  • Proof that a limit is achievable with guidance and resources
  • A strong scientific rationale
  • A national committee to support OEL implementation and inter-provincial harmonization
  • Available, up-to-date measurement techniques and data
  • A consensus OEL recommendation

The findings of the environmental scan indicate a trend towards the adoption and implementation of more protective OELs for DEE. Based on evidence of increased lung cancer risk at very low levels, we recommend that Canadian jurisdictions move towards an OEL based on elemental carbon of 20 µg/m3 for the mining industry* and 5 µg/m3 for other workplaces to protect worker health.

For more information, the full report is available here. Our commentary that features this work, titled “Canada Should Move Toward Adopting Harmonized Evidence-Based OELs to Consistently and Adequately Protect Workers”, is available here.

*The higher OEL recommended for the mining industry takes into account the feasibility of implementation in this industry that will have particular challenges and is meant as a interim target in a staged approach to eventually have one harmonized OEL for all workers.

 

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The CAREX Canada team offers two regular newsletters: the biannual e-Bulletin summarizing information on upcoming webinars, new publications, and updates to estimates and tools; and the monthly Carcinogens in the News, a digest of media articles, government reports, and academic literature related to the carcinogens we’ve classified as important for surveillance in Canada. Sign up for one or both of these newsletters below.

CAREX Canada

School of Population and Public Health

University of British Columbia
Vancouver Campus
370A - 2206 East Mall
Vancouver, BC  V6T 1Z3
CANADA

© 2022 CAREX Canada
Simon Fraser University

Stanford water expert discusses wildfire’s threat to water quality

Stanford News – When fires jump from forests and grasslands to urban areas, they incinerate household and industrial items such as computers and cars, leaving behind a stew of chemicals and heavy metals. Rain can wash this into streams, rivers and municipal water treatment systems unprepared to deal with the toxic deluge. Heavy sediment loads from wildfire-related erosion can also clog water systems and strain treatment requirements.
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Subscribe to our newsletters

The CAREX Canada team offers two regular newsletters: the biannual e-Bulletin summarizing information on upcoming webinars, new publications, and updates to estimates and tools; and the monthly Carcinogens in the News, a digest of media articles, government reports, and academic literature related to the carcinogens we’ve classified as important for surveillance in Canada. Sign up for one or both of these newsletters below.

CAREX Canada

Faculty of Health Sciences

Simon Fraser University
Harbour Centre Campus
2602 – 515 West Hastings St
Vancouver, BC  V6B 5K3
CANADA

© 2020 CAREX Canada

Evidence-based occupational health and safety interventions: a comprehensive overview of reviews

Occupational and Environmental Medicine – The aim of this overview of reviews is to provide a comprehensive basis to inform evidence-based decision-making about interventions in the field of OHS. According to the study authors, this is the first comprehensive overview of behavioural, relational and mixed interventions and their effectiveness in preventing occupational injuries and diseases. It provides policymakers with an important basis for making evidence-based decisions on interventions in this field.
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Subscribe to our newsletters

The CAREX Canada team offers two regular newsletters: the biannual e-Bulletin summarizing information on upcoming webinars, new publications, and updates to estimates and tools; and the monthly Carcinogens in the News, a digest of media articles, government reports, and academic literature related to the carcinogens we’ve classified as important for surveillance in Canada. Sign up for one or both of these newsletters below.

CAREX Canada

Faculty of Health Sciences

Simon Fraser University
Harbour Centre Campus
2602 – 515 West Hastings St
Vancouver, BC  V6B 5K3
CANADA

© 2020 CAREX Canada

The price of recycling old laptops: Toxic fumes in Thailand’s lungs

New York Times – The e-waste industry is booming in Southeast Asia, and despite a ban on imports, Thailand is a center of the business. In addition to the danger posed to workers, if some types of electronic waste aren’t incinerated at a high enough temperature, dioxins, which can cause cancer and developmental problems, infiltrate the food supply. Without proper safeguarding, toxic heavy metals can also seep into the soil and groundwater.
Read more »

Subscribe to our newsletters

The CAREX Canada team offers two regular newsletters: the biannual e-Bulletin summarizing information on upcoming webinars, new publications, and updates to estimates and tools; and the monthly Carcinogens in the News, a digest of media articles, government reports, and academic literature related to the carcinogens we’ve classified as important for surveillance in Canada. Sign up for one or both of these newsletters below.

CAREX Canada

Faculty of Health Sciences

Simon Fraser University
Harbour Centre Campus
2602 – 515 West Hastings St
Vancouver, BC  V6B 5K3
CANADA

© 2019 CAREX Canada